Study On Top Deflection Of Tray Column And Fluid Flow Condition On Inclined Tray

A tray will incline owing to bending deflection or vibration of the tower when the tower is subjected to the lateral loads. The centroid of the liquid medium on the tray deviates from the axis of the tower, which makes further changes to the deflection curve of the tower.The eccentricity formula of centroid of liquid medium was deduced, considering the non-uniform liquid layer on the inclined tray. The top deflection of the tray column under working condition was solved, using superposition principle of mechanical and the self-edit program. The effects of physical parameters of the liquid medium and structure parameters of the tower body on additional top deflection were studied.The transfer matrix of the tray column under working conditions was derived, thinking about the additional eccentric inertial force created by the eccentric of liquid medium. Natural vibration period of the tray column under working condition was solved with self-compiled program. The effect of the mass of liquid medium on natural vibration period was researched. Taking advantage of the transfer matrix method, it was summarized that natural vibration period of the tray column under working condition was greater than that without considering the eccentric of liquid medium.The gas and liquid phases were modelled in the VOF framework as two interpenetrating phases. Good consistency was found between the flow fields measured with Laser Doppler Velocimeter(LDA) and the results of numerical simulation. The clear liquid height determined from the simulations was in reasonable agreement with the experimental measurements carried out for air-water in a round tray and the result of the Francis formula. The circulations were reproduced from the simulation results. The simulation results show that the center of circulation exists in the middle of the tray when the tray is horizontal, however, the center of circulation is located at the thick liquid layer with the oblique tray. The maximum of the turbulent kinetic energy is located at the center of circulation. Compared with the horizontal tray, the circulation area is bigger when the liquid flow and the inclination direction of the tray are the same, but when they are opposite the circulation area is smaller. The percentage of circulation area to the tray area can obviously be decreased, along with increasing the liquid weir loads. There is an obvious enlargement of the circulation area when the height is over the inlet along Z direction.Based on Eulerian model, the distribution of the liquid field was simulated where the gas phase passing through non-uniform thickness liquid layer on the inclined tray. Good agreements of pressure drop distributions between the simulation results and experimental data. The distribution of gas phase in the liquid layer is in form of gas coning in the initial stages of the gas phase into the liquid phase, furthermore, the gas coning is bigger and the gas phase velocity is higher in the thin liquid layer. The gas phase in thin layer crosses priority liquid layer with continuous injection of gas phase. The weeping increases with the increase of the tray tilt, and the inclined tray has the lower operating limit. The influence of the tray inclination on the entrainment can be decreased with the increase of gas loads.